In order for us to provide better support, we need to see the log generated by citra. This guide will walk you through how you can obtain the log file: How to Upload the Log File
It was Nightly 1782 that last supported OpenGL 3.3 (Citra is currently using OpenGL 4.3). But regardless, without more info on their system, they may very well be using old GPU drivers. So updating them would maybe allow them to use the latest Citra builds. Which is obviously preferable. However, they refuse to provide more information on their system, nor have they asked me where to find the info if they don’t know where to find it.